solve for b: a=1/2h(b+c)

Question

solve for b: a=1/2h(b+c)

Answer 1

a=(1/2)h(b+c) <== Is this what you want?

Multiply both sides by 2/h.

2a/h = b+c

Add -c to both sides,

2a/h - c = b

So, b = 2a/h - c by the property of symmetry.

Answer 2

a = 1/2h(b+c)  (orig problem)

a = hb/2 + hc/2  (multiply b+c by 1/2h, or h/2)

a - hc/2 = hb/2 (subtract hc/2 from both sides, to get only b term alone)

2a - hc = hb  (multiply both side by 2)

(2a-hc)/h = b, or b = 2a/h - c  (divide both sides by h)